A misfire condition and its corresponding misfire trouble code can be the result one of many different components having failed... that troubleshooting its cause can seem almost impossible. For example, the misfire code could be caused by a bad Coil-on-Plug (COP) ignition coil, or a bad fuel injector, or in one engine cylinder having very low compression, and the list could go on...
According to Spam's website, the canned meat contains only 6 ingredients: already-cooked pork (two different cuts: pork shoulder and ham), salt, water, potato starch (to keep the meat moist), sugar and sodium nitrite (a common preservative).
On to your questions. The common assumption is that Spam is made of stuff even pigs don't like to admit they've got. Not so, says a spokeswoman for Hormel Foods, which manufactures Spam. It contains a mixture of ham and chopped pork shoulder. (Ham is the pig's thigh; pork is everything else.) Ham is Hormel's top-of-the-line product, and Spam was created in 1937 partly to use up what was left of the pig after the ham had been removed. But only the wholesome parts.